Exemplary embodiments relate to a design structure, and more specifically, a design structure of circuit for clock recovery from Bipolar RZ data.
Return-to-zero (RZ) describes a line code used in telecommunications signals in which the signal drops (returns) to zero between each pulse. This takes place even if a number of consecutive 0's or 1's occur in the signal. The signal is self-clocking. This means that a separate clock does not need to be sent alongside the signal, but may use twice the bandwidth to achieve the same data-rate as compared to non-return-to-zero format. The “zero” between each bit is a neutral or rest condition.
A non-return-to-zero (NRZ) line code is a binary code in which 1's are represented by one significant condition (usually a positive voltage) and 0's are represented by some other significant condition (usually a negative voltage), with no other neutral or rest condition. The pulses have more energy than a RZ code. Unlike RZ, NRZ does not have a rest state. NRZ is not inherently a self-synchronizing code, so some additional synchronization technique (for example a run length limited constraint or a parallel synchronization signal) must be used to avoid bit slip.